<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>


<script type="text/javascript">

  function sub1(str) {
    let split = str.split('=');
    return split[0].substring(1, split[0].length);
  }

  function sub2(str) {
    let split = str.split('=');
    return split[1].substring(0, split[1].length - 1);
  }

</script>
</body>
</html>